Electronic Control System Signature, ISX and QSX15 Engines – FAULT CODE 755

Fuel Injector


Fault Code: 755
PID: P157
SPN: 157
FMI: 7/7
LAMP: Yellow

Incorrect fueling was detected on the front three cylinders.

Engine will misfire.

Fuel Injector

Circuit Description

The electronic control module (ECM) supplies voltage to open the fueling actuators for a short length of time. This allows a short pulse of fuel to flow to the injector. The injector then injects this fuel into the cylinder for combustion.

Component Location

The injectors are located in the cylinder head under the valve cover.

Shop Talk

The ECM measures the amount of fuel metered into each injector by using the front fuel rail pressure sensor. If the ECM detects that no fuel is entering an injector, the fault code is activated.

This fault can be caused by air in the fuel.

Refer to Troubleshooting Fault Code t05-755.

Last Modified:  26-Oct-2010